I'm interested in armour and helmets of palace guard of Justinian The Great (excubitors and scholae) but I have a big problem with literature. I can't find anywhere two books which I really need:

Frank, R. I., Scholae Palatinae (Rome, 1969)

Haldon, J. F., Byzantine Praetorians (Bonn, 1984)

I will be grateful for any help

I read only now.
the Imperial Guard at the time of Justinian. From primary sources, can not be explained by a well-defined prototype.
Example: The Imperial Guard of Justinian in the mosaics of Ravenna (S. Vitale) have no armor but luxurious uniform, spear and shield, no helmet.
A few years later the scholares of Justin II describes armed with a two-edged ax, "Solae Apparent posr scute bipennes" (Flavius Cresconius Corippus - Iohannidos librycis seu de Bellis, books IV, 560 - Cantabrigiae - 1970.
The excubitores with golden shields and spears, swords and armor, helmets, golden, red crest, high boots. (De Cerim. I, 93, p. 427)
Certainly we know that to be enrolled in these units, the soldiers had to have a wonderful physical and strong. The same Justin, was drafted in excubitores.
Personally I think a lot of different training these units to war. They were certainly not equal to those of the late Empire.